Fuel feeding apparatus



1946' I A. o. ANDERSON 2,412,193

FUEL FEEDING APPARATUS Filed Aug. 2a, 1945 4 Sheets-Sheet 1 IN V EN TOR.

A T TORNEYJ Dec. 10, 1946. A. O. ANDERSON FUEL FEEDING APPARATUS FiledAug. 23, 1945 4 Sheets-Sheet 2 INVENTOR. flc'f/zur Qflndewou 21amzfxdaaw AT TOPNE YU' Dec. 10, 1946.

A. o. ANDERSON 2,412,193

FUEL FEEDING APPARATUS Filed Aug. 23, 1945 4 Sheets-Sheet 3 IN V EN TOR.

ATTOPNE YS Dec. 10, 1946. Q ANDERSON 2,412,193

FUEL FEEDING APPARATUS Filed Aug. 23, 1945 4 Sheets-Sheet 4 ATTORNEYJPatented Dec. 10, 1946 UNITED STATES PATENT OFFICE (Granted under theact of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 7Claims.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to me ofany royalty thereon.

The present invention relates generally to the art'of fuel feeding. Moreparticularly, it providesfor an improved attachment for a solid fuelfeeding apparatus of ,a standard heating furnace which comprises meansfor speedy and easy access to the interior of the feed mechanismhousing.

Specifically, the improved attachment includes a hinged interiorlytapered combination coupling and coal chamber adapted to house the feedmechanism of a conventional automatic stoker. The chamber is providedwith releasable locking means-and may be opened for exposing said feedmechanism through 360 by manual manipulation of the locking means.

In the past in connection with the operation of solid fuel stokers,especially with the underfeed type, it occasionally has been found thata relatively-large piece of steel or other hard material has becomemixed with coal in the bin or hopper in which it was contained in such amanher that the foreign matter has been fed along with the coal into thefeeding tube where it sometimes came in contact with the fuel feedingmechanism and became wedged between the fuel feeding mechanism and thetube housing it, in such a manner as to stop rotation of said fuelfeeding mechanism. When this occurs a shear pin normally employed in thefuel feed drive shaft is broken, thereby severing the connection betweenthe prime mover and the drive shaft. In such a contingency, it isusually necessary to shovel all of the coal away from the fuel outlet inthe bin, when such a receptacle is used for the fuel, and to employ alever arm or other tool for manually reversing rotation of the torquescrew or other feeding means to disengage the steel or other foreignobject. In cases where a hopper is used it is usually necessary tocompletely unload the hopper in order to gain access to the interior ofthe housing of the fuel feeding mechanism. After removal of a foreignbody a new shear ,pin may be inserted in the driving shaft, the hopperreloaded and the stoker again placed. in operation.

Obviously the above described process is an ineillcient andtime-consuming repair job. Accordingly, one-of theobjects of the presentinvention isthe construction of a device providing convenient and speedyaccess to the fuel'feed ingmechanism of an automatic stoker for facil- 2itating repair and/or adjustment necessary to assure smooth andefiicient operation of the fuel feeding mechanism.

Another object of my invention is to furnish a sectioned combinationcoupling and fuel chamher for the conveyor tube of an automatic stokerwhich may be opened substantially through 360 by manual release of asimple locking means.

A further object of the present invention is the provision of a modifiedfuel conveyor tube for an automatic stoker adapted to receive a readilyremovable flanged coupling and fuel chamber.

, An additional and important object of my invention is the constructionof a coupling forthe conveyor tube of an automatic stoker adapted forcompression of the fuel into the grooves of the fuel feeding meanssubstantially entirely within the coupling.

A still further object .of my invention is the provision of acombination coupling and fuel chamber adapted for installation intoexisting stoker assemblies with relatively few alterations to theexisting plant.

' Preferred embodiments of my invention whereby I attain the above andother and further objects are illustrated in the accompanying drawingsin which like numerals refer to like parts throughout the several viewsand wherein:

Fig. 1 is a schematic layout showing one form or arrangement of a solidfuel bin or hopper, a fuel feeding tube, a furnace and the attachmentconstituting the improvement of the present invention;

Fig. 2 is a perspective view illustrating the means of application ofthe fuel chamber vcoupling to the conveyor tube of a stoker and showsone form of lockingmeans used to retain the coupling member in lockedrelationship relative to said conveyor tube; v

Fig. 3 is a side elevation, partly in section, showing the interiorlytapered coupling member and the manner in which it is attached to theconveyor tube of a stoker;

Fig. 4 is an end view .of the hinged coupling device in opened position;

Fig. 5 is an end view of the coupling device of Fig. 4 showing thedevice in closed and locked position;

Fig. 6 is a view of the conveyor andfuel feed tubes of a stoker with thehinged coupling member completely removed;

Fig. 7 is a view similar to Fig. 6 but showing the hinged couplingsecured tothe fuel feed and conveyor tubes; and

Fig. 8 illustrates an alternative construction for locking the hingedsections of the coupling chamber.

Referring to Fig. 1, the numeral l designates a bin or hopper for solidfuel. A relatively short cylindrical fuel feeding tube 2 is connected tothe bin and has secured thereto the improved attachment designatedgenerally by the reference numeral 3 constituting the present inventionas hereinafter described. The numeral 4 indicates a conventionalfurnace. The fuel bin I is provided with a generally circular fueloutlet to which is connected the fuel feeding tube 2 as by means of anannular flange member 5 adapted to be secured to the fuel bin l by meansof any suitable fastening means'such as bolts passed through apertures 8formed in the annular flange member. The attachment 3 comprises acombination coupling and fuel chamber 1 which is adapted to form aconnection between the free end of the fuel tube 2 and a fuel conveyortube 8 and also to house fuel feeding mechanism such as a torque screwor worm 8 (Fig. 2) The conveyor tube 8 is of smaller diameter than thetube 2, for a reason which will hereinafter become apparent.

The member '1, preferably made of cast iron, is generally similar to thehollow frustum of a cone and is interiorly tapered as at ill (Fig. 3).The inside diameter of the fuel chamber 1 at the end of the taper l0-adiacent the entrance to the conveyor tube 8 preferably is slightly lessthan th inside diameter of the latter. With this construction anyimpediment to continued operation of th feeding means which may becontained in the fuel being fed by the worm 9 will be trapped in thechamber 1 without being passed on to the tube 8 where it would bedifflcult to retrieve it. The inside surface of the chamber 1 may beeither smooth or ribbed. The chamber may consist oftwo or moresubstantially identical sections (twoin the present instance) indicatedby numerals I l and fiend hingedl-y connected as at l3 by means ofa-pintie- M. Eachof'these sections is provided with twosemicircularcollar elements I! and positioned at opposite ends'of the chamber. Thesecollar elements are g-rooved on their inner peripheries in the mannerindicatedat i'i'in Fig. 3', which construction adapts them forcooperation with chamfered annular flanges or ribs i-fland i8 formedrespectively at one end ofthe fuel feed tube 2 and th conveyor tube 8for securing the coupling in position and for preventing axialdisplacement thereof. As shown most clearlyin Figs. 2, 3-, and '6 theflange 18 is formed on-the' end-of! an adapter member 80- having itsother end formed-as asleeve-fitting around the outside of'the open endof tubes and secured thereto by any suitable means such as welding.

Various devices for maintaining the hinged sections it and i 2 oftheschamber 1" in locked relation. relative to eachother may beemployed. Figs. 1-5 and 7 show one form of the locking device and Fig. 8shows an alternative form which I have chosen to illustrate and describeherein.

"The device shown in Figs. 1-5 and 7 comprises a bolt 20 pivotallyconnected at one end as'by means-of a pin '21- to a substantially Ushaped deg'zz which 'may be formed integralfwith the body portion of thesection H of the coupling chamber 'l'-.- The bolt 20 is threaded at oneend and is adapted toreceive a complementary interiorly threaded tubularlocking member 23-and a-washer M and to fit into a second substantiallyU-shaped dog 24 formed integral with the body portion of the othersection i2 of the chamber 1. The dogs 22 and 24 may be reinforced intheir connections to the collars i5 and (6 respectively as by means ofinclined flanges or ribs 25 and 26 as shown in Fig. 2. The two sections.ii and i2 of the coupling chamber 1 are adaptedto be releasably lockedby manipulation of a handle 21 positioned adjacent one end of thelocking member 23 and extending therethrough, the locking member beingadapted for projection against the washer 3i by the cooperation of. itsinteriorly threaded portion with the threaded part of the bolt 20.

The coupling chamber 1 may be further secured against rotation relativeto the ribs I8 and i9 by means of a pair of dowel pins 28 adapted topinthe collars l5 and I6 respectively to the annular flanges I8 and ill bymeans of a slot in each of the latter, as shown at 29 in Fig. 2. The pin28- is preferably made of soft. steel and. may be inserted at anyconvenient point toss cure the desired result. This pin is. preferablysubstantially equal in strength to the shear pin usually employed instokers to break the connection between the prime mover and the fuelfeed driveshaft in emergencies which may arise through malfunctioning ofthe fuel feeding mechanism. through failure of the screw or wormcarrying shaft to rotate due to an obstruction in the fuelto be fed orotherwise, as is well understood in the art. It will be-evident'that byreason of the tapering of the chamber solid fuelfed into the interiorthereof will lie-compressed into the spiral grooves of the feed screw 9substantially entirely within the chamber. Consequently if there is anyforeign object mixedwith the fuel it will be engaged, if at all, betweenthe feed screw and its surrounding enclosure at some point within thefeeding chamber. Thus should lube-necessary to remove any obstructionaffecting smooth continuous operation of? the fuel feeding screw it canbe easily and quickly accomplished-by releasing the locking'bolt 2a,disengaging it from the dogs 22 and 24- and removing the hinged chamberI entirely as shown in Fig. 6.-

Fig. 8 shows a. modified form of attachment designated by the numeral 1aand having allthe characteristicsof the attachment I except-thattwolocking bolts and four dogs are-employed; Corresponding similar partsaredesignated by corresponding reference characters towhich the exponentai'has -been added;

As previously mentioned-one of the important features of my inventionresides in the ease and simplicity with which itmay beincorporated intoknown types of fuel feeding assemblies with but slight modifications tothe existing plant; For example, a typical installation priorto-modification to incorporate my improved coupling will bear-rangedinsuch manner thatthetube- 8 is constructed as a continuous singlemember having enlarged flange means secured to its end adapted forfastening directly tothe-hopper I-'. It isaccordingly onlynecessaryin-such cases toremove the enlarged flange and substitute my doubleflanged cylindrical member 2 therefor; sever a short section from thetube Elfand secure the adapter flange 30 in place on the-sevcred end oftube 8. "I-he assembly will then be inthe condition illustrated in Fig.6 in readiuses toreceive my improved coupling device '3 which may thenbe fitted over the flanges l8 and i8 and securely but i-eleasesblymelted in place by-the-bolt- 20 and shear pins-28. his-there are manyknown types of stoker assemblies the details may vary slightly accordingto the different modifications encountered but in each case thealterations necessary will be of a relatively minor character andextent.

Although I have illustrated and described herein only preferredembodiments of my coupling chamber, it is obvious that others of manytypes and variably positioned, could be used depending upon the lengthof the fuel feed tube and -of the conveyor tube. Also my invention isadapted among other things for use in overfeed. underfeed and centralfeed stokers and it is not therefore my intention to be limited to theunderfeed type illustrated.

Many alterations and modifications of the present invention will nodoubt occur to those skilled in the art and I do not therefore desire tobe restricted by the precise disclosure made herein. Accordingly it ismy intention to be limited only by the prior art and the appendedclaims.

I claim:

1. In a stoker for feeding solid fuel from a fuel source to a furnace, afuel inlet tube, means for connecting one end ofsaid fuel inlet tube toaid fuel source, an annular rib on the other end of said fuel inlettube, a fuel conveyor tube, one end of which is adapted to be connectedto a furnace, an annular rib on the other end of said conveyor tube,said ribbed ends of said inlet and conveyor tubes being coaxially spacedapart, fuel-feeding mechanism housed by said tubes but exposed at thespaced apart ribbed ends of said tubes, an interiorly tapered fuelchamber interposed between the ribbed ends of said tubes and havingfirst and second separable sections, said fuel chamber being adapted tohouse that portion of said fuel-feeding mechanism between the ribbedends of said tubes and to compress fuel between the walls of saidchamber and said fuel-feeding mechanism substantially entirely withinsaid chamber, means for hingedly connecting said sections whereby theymay be opened and closed through 360 about the aforesaid portion of saidfuel-feeding mechanism, keeper means on each of said sections,releasable latch means cooperable with said keeper means for releasablylocking said sections in closed position, a pair of complementary coilarelements at each end of said fuel chamber sections, means forming agroove on the interior of each of said collar elements, each pair ofsaid collar elements being adapted respectively to encircle the ribbedends of said tubes with said grooves embracing said ribs forsubstantially preventing axial displacement of said fuel chambersections relative to said tubes, and means for confining said fuelchamber against rotation relative to said tubes.

2. In a stoker for feeding solid fuel from a fuel source to a furnace, afuel inlet tube, means for connecting one end of said fuel inlet tube tosaid fuel source, an annular rib on the other end of said fuel inlettube, a fuel conveyor tube, one end of which is adapted to be connectedto a furnace, an annular rib on the other end of said conveyor tube,said ribbed ends of said inlet and conveyor tubes being coaxially spacedapart, fuel-feeding mechanism housed by said tubes but exposed at thespaced apart ribbed ends of said tubes, an interiorly tapered fuelchamber interposed between the ribbed ends of said tubes and havingfirst and second separable sections, said fuel chamber being adapted tohouse that portion of said fuel-feeding mechanism between the ribbedends of said tubes and to compress fuel between the walls of saidchamber and said fuelfeeding mechanism substantially entirely-withinsaid chamber, means for hingedly connecting said sections whereby theymay be opened and closed through 360 about the aforesaid portion of saidfuel-feeding mechanism, releasable latch means for releasably lookingsaid sections in closed position, a pair of complementary collarelements at each end of said fuel chamber sections, means forming agroove on the interior of each said collar elements, each pair of saidcollar elements being adapted respectively to encircle the ribbed endsof said tubes with said grooves embracing said ribs for substantiallypreventing axial displacement of said fuel chamber sections relative tosaid tubes, and means for confining said fuel chamber against rotationrelative to said tubes.

3. In a stoker for feeding solid fuel from a fuel source to a furnace, afuel inlet tube, means for connecting one end of said fuel inlet tube tosaid fuel source, an annular rib on the other end of said fuel inlettube, a fuel conveyor tube, one end of which is adapted to be connectedto a furnace, an annular rib on the other end of said conveyor tube,said ribbed ends of said inlet and conveyor tubes being coaxially spacedapart, fuelfeeding mechanism housed by said tubes but expose-d at thespaced apart ribbed ends of said tubes, an interiorly tapered fuelchamber inter-' posed between the ribbed ends of said tubes, said fuelchamber being adapted to house that portion of said fuel-feedingmechanism between the ribbed ends of said tubes and to compress fuelbetween the walls of said chamber and said fuelfeeding mechanismsubstantially entirely within said chamber, means providing for interioraccess to said chamber to expose a portion of said fuelfeeding mechanismbetween the ribbed ends of said tubes, a pair of collar elementsrespectively at opposite ends of said fuel chamber, means forming agroove on the interior of each of said collar elements, said collarelements being adapted respectively to encircle the ribbedends' of saidtubes with said grooves embracing said ribs for substantially preventingaxial displacement of said fuel'chamber sections relative to said tubes,and means for confining said fuel chamber against rotation relative tosaid tubes.

4. An attachment for a stoker adapted to be releasably secured to a fuelconveyor tube of said stoker, said attachment constituting a housing fora portion of the fuel feeding mechanism of the stoker and comprising afuel chamber having first and second separable sections, means forsubstantially preventing axial displacement of said sections relative tosaid fuel conveyor tube, means for hingedly connecting said sectionswhereby they may be opened and closed relative to each other forexposing a portion of said fuel feeding mechanism through 360, keepermeans on each of said sections and latch means cooperable with saidkeeper means for releasably locking said sections relative to eachother.

5. An appliance for an automatic stoker adapted to feed fuel to afurnace from a fuel source by means of fuel feeding mechsnism housed ina conveyor tube, said appliance constituting a housing for a portion ofthe fuel feeding mechanism and comprising an interiorly tapered fuelchamber, means for connecting one end of said chamber to said conveyortube and coaxially therewith, means for connecting the other end of saidchamber to a fuel inlet tube, said chamber being adapted to compressfuel between the walls thereof and the fuel conveyor means substantiallyentirely within said chamber, and means for disconnecting said fuelchamber from the conveyor tube and the fuel inlet tube for exposing 'theaforesaid chamber housed portion of the fuel feeding mechanism through360'.

6. In combination, in a stoker for feeding solid fuel from a fuel sourceto a furnace and having fuel feeding mechanism, an interiorly taperedfuel chamber having means for access to the interior thereof and adaptedto house a portion of said fuel feeding mechanism, means for connectingsaid fuel chamber to said fuel source, means for connecting said fuelchamber to said furnace, said tapered chamber being adapted to compress8 fuel fed therethrough between the walls thereof and the fuel feedingmeans substantially entire- 1r. within said chamber.

'7. A device for a stoker adapted to be releasably secured at one end toa fuel conveyor tube in said stoker, and at its other end to a fuelinlet tube from a fuel source, said device constituting a housing for aportion of the fuel feed mechanism of said stoker and comprising atapered fuel chamber having at least two sections adapted to be openedand closed relative to each other, and means including the aforesaidsections for disconnecting said fuel chamber from said conveyor tube andsaid fuel inlet tube for ex-' posing said fuel feeding mechanism through360.

ARTHUR O. ANDERSON.

